Lagering outdoors?

Homebrew Talk - Beer, Wine, Mead, & Cider Brewing Discussion Forum

Help Support Homebrew Talk - Beer, Wine, Mead, & Cider Brewing Discussion Forum:

This site may earn a commission from merchant affiliate links, including eBay, Amazon, and others.
Aug 7, 2007
Reaction score
Washington, DC
I brewed a Kolsch yesterday, my first partial mash from an AHS kit. Went reasonably well, though the OG was higher than expected and the wort was very cloudy, even after cooling and filtering through a grain bag.

What I'm wondering now is about ageing in the secondary, which I know should be done at lager temperatures. I don't have a lagerator or a basement, so I was hoping to put it outside on my apartment balcony (the average low for DC in February is 26, high is 47).

I know that daily temperature fluctuation is bad news for the beer, so I'm hoping I can come up with some way of insulating the carboy a little bit.

Any advice?
Bury it? You'd have to get pretty deep, but it's doable.

You could find a cave....


a cave...
Not particularly realistic in the city, sadly.

I'm looking for some other way to insulate the carboy. My first thought was to stick it in a bucket of cold water and keep it covered , but I'm not sure what would happen to the Better Bottle if the water around it froze...
are you using Wyeast 2565 Kolsch yeast?

its not a true lager yeast...more like a pseudo lager yeast. it'll turn out fine if you can keep it at 50f during part of the secondary. it just helps the yeast flocculate for a clearer beer.
White Labs WLP029, actually. I'd be thrilled with a 50 degree secondary, but I'm not sure how I'd get that without putting it outside -- hence my concern about the 20 degree daily fluctuation in ambient temperature.
maybe you could wrap it in a sleeping bag or some other insulator to dampen the day/night temp fluctuation. Even fiberglass pink panter stiff would probably help.
Maybe you could do like ander recommended and get a sleeping bag for the first 14 days for the primary fermentation to fight off the fluctuation of temperature. I would recommend using a digital thermometer to keep track of your temp. Then when you get ready to lager you can put it in a bucket of water and leave it for a while. IMO I don't think 26 degrees is enough to freeze it solid, if the water does freeze I don't think your beer will freeze. If you are still concerned, you could just keep some kind of top on it to keep the direct 26 degree air off the water.
Thanks, everyone. I like the sleeping bag idea. Anyone have any thoughts on whether it's dangerous to have a better bottle carboy stuck in water that freezes?
The problem with bottles of any kind and freezing things is that the water on the top of the large vessel will freeze before the bottom. (ice floats)

A friend had to freeze some liquid samples in the lab, and used Erlenmeyer flasks. The smaller area at the top froze first, and then the bottom. This was a problem, as water expands when it freezes. All 80 of the samples were ruined because the flasks had their bottoms blown off when the lower half of each sample began to freeze.

If it's in a larger vessel filled with water, fluctuation would be lessened, but possibly not enough.

OOO! Try one of those fish tank heaters in the larger vessel!

Try it on a smaller scale!
I built a simple insulated box out of 50mm (2") styrofoam sheets and a roll of duct-tape. I covered the inside with a layer of aluminum foil to keep out the sunlight.

My box is pretty big (I have a huge balcony) so I can fit three buckets/carboys without problem. Since it gets really cold up here I also added a cheap 200W heater (frost guard) and a styrofoam divider so I can have one batch fermenting and two in lower temp conditioning.

Definitely insulate and shield from light. Go down to the fish market (near the mall)where they discard lots of large styrofoam cartons, get some duct tape and you should be good to go. I 'm in maryland and serve beer out a really cold cellar room. Temps are 40-50 all winter, great serve temps. Good luck
I agree that an insulated box is probably the best way to go. I'd also suggest doing something to prevent freezing. I came across a cheap device on clearance at Lowes that looked a little like a timer. It's intended use was to plug a lamp into it and set the temperature knob to 40 or 50ºF so that if your heater was broke while you were away, the neighbors would see the light on and call you. It actually said that on the package but my neighbors would sooner shoot the light out with a BB gun before calling me (but I digress). Anyway, if you plugged a 20 watt bulb into this thing, it would provide enough heat to keep the interior temp up to say 40. It was only $16 so much cheaper than a typical controller.
I wired a cheap furnace thermostat to a light bulb. I use it in an old non-working fridge that sits outside. I can set and hold just about any temp I want. I think I spent $25 or so on the thermostat, light socket and lamp cord. I don't see why you couldn't build a box out of foam insulation to cover the carboy and use the lightbulb method for heating. Another option for heating it, would be to set your carboy on top of an electric heating pad and then cover it whole thing with a blanket or foam box.
Great suggestions on the insulation, thanks! I think I'll take balto charlie's advice and check out the fish market.

Unfortunately I don't have any power outlets outside, so I probably can't do anything electrical. I'm not sure how worried I should be about the beer freezing, though, with average daily highs close to 50 -- it seems like it'd take many hours at a pretty cold temperature for 5 gallons to freeze (especially once insulated).
I got myself a big 36 gallon plastic tub from Home Depot and filled it with water. I think that should take care of most of the temp fluctuation.
This is what I came up with while falling asleep. I just noticed you can't do electric stuff outside, but here's a try.

Yay, MSpaint!


Of course you'd have to use a more stable large vessel.... I'm just lazy.